A thermogravimetric analyzer was used to conduct a kinetic investigation of rice husk pyrolysis. The major goal is to investigate the reaction kinetics of rice husk at various heating rates in an inert 99.5 percent ni...A thermogravimetric analyzer was used to conduct a kinetic investigation of rice husk pyrolysis. The major goal is to investigate the reaction kinetics of rice husk at various heating rates in an inert 99.5 percent nitrogen atmosphere. Kinetics’ importance can be explained by the fact that it provides evidence for chemical process mechanisms. Understanding reaction mechanisms can help you figure out the best way to get a reaction to happen. Furthermore, it is of fundamental scientific interest. The samples were heated at different heating rates of 5, 10, 20, and 40 K min<sup>-</sup><sup>1</sup> from ambient temperature to 973 K. The thermal degradation characteristics and the kinetic parameter were determined. The values show that the activation energy (E<sub>a</sub>) and pre-exponential factor (A) vary with heating rates and temperature.展开更多
Utilizing the material of monthly means of the three primary kinetic energy modes over the whote globe at 500 hPa during the nine years of 1980-1988, both the rapid seasonal changes and the interannual variability in ...Utilizing the material of monthly means of the three primary kinetic energy modes over the whote globe at 500 hPa during the nine years of 1980-1988, both the rapid seasonal changes and the interannual variability in tie general circulation in terms of the energy modes have been investigated, with special attention paid to the unusual year 1983, Two main results are obtained. One, there are remarkable seasonal rapid changes over the Northern Hemisphere, occurring ganerally in April and October. The other, among the nine years of 1980-1988, 1983 is the only one with unusual energy modes and remarkably abnormal seasonal changes.展开更多
The recent studies of direct alcohol/ether synthesis process in slurry reactors were reviewed,and the research work in our laboratory was carried out in this paper.a global kinetics model for direct dimethyl ether(DME...The recent studies of direct alcohol/ether synthesis process in slurry reactors were reviewed,and the research work in our laboratory was carried out in this paper.a global kinetics model for direct dimethyl ether(DME)synthesis from syngas over a novel Cu-Zn-Al-Zr slurry catalyst was established according to the total of 25 experimental data,and a steady-state one-dimensional mathematical model was further developed in bubble column slurry reactor(BCSR),which was assumed that the bubble phase was plug flow,and the liquid phase was fully mixed flow.The numerical simulations of reactor design of 100000 t/a dimethyl ether pilot plant indicate that higher pressure and lower temperature were favorable to the increase of CO conversion,selectivity of dimethyl ether,product yield and height of slurry bed.The optimal operating conditions for DME synthesis process were obtained:reaction temperature at 240℃,reactor pressure at 5 MPa and reactor diameter of 2.5 m.展开更多
文摘A thermogravimetric analyzer was used to conduct a kinetic investigation of rice husk pyrolysis. The major goal is to investigate the reaction kinetics of rice husk at various heating rates in an inert 99.5 percent nitrogen atmosphere. Kinetics’ importance can be explained by the fact that it provides evidence for chemical process mechanisms. Understanding reaction mechanisms can help you figure out the best way to get a reaction to happen. Furthermore, it is of fundamental scientific interest. The samples were heated at different heating rates of 5, 10, 20, and 40 K min<sup>-</sup><sup>1</sup> from ambient temperature to 973 K. The thermal degradation characteristics and the kinetic parameter were determined. The values show that the activation energy (E<sub>a</sub>) and pre-exponential factor (A) vary with heating rates and temperature.
基金This work is supported by the Doctorial Program Foundation of the Institution of Higher Education.
文摘Utilizing the material of monthly means of the three primary kinetic energy modes over the whote globe at 500 hPa during the nine years of 1980-1988, both the rapid seasonal changes and the interannual variability in tie general circulation in terms of the energy modes have been investigated, with special attention paid to the unusual year 1983, Two main results are obtained. One, there are remarkable seasonal rapid changes over the Northern Hemisphere, occurring ganerally in April and October. The other, among the nine years of 1980-1988, 1983 is the only one with unusual energy modes and remarkably abnormal seasonal changes.
基金supported by a grant from the Major State Basic Research Development Program of China(973 Program,No.2005CB221205).
文摘The recent studies of direct alcohol/ether synthesis process in slurry reactors were reviewed,and the research work in our laboratory was carried out in this paper.a global kinetics model for direct dimethyl ether(DME)synthesis from syngas over a novel Cu-Zn-Al-Zr slurry catalyst was established according to the total of 25 experimental data,and a steady-state one-dimensional mathematical model was further developed in bubble column slurry reactor(BCSR),which was assumed that the bubble phase was plug flow,and the liquid phase was fully mixed flow.The numerical simulations of reactor design of 100000 t/a dimethyl ether pilot plant indicate that higher pressure and lower temperature were favorable to the increase of CO conversion,selectivity of dimethyl ether,product yield and height of slurry bed.The optimal operating conditions for DME synthesis process were obtained:reaction temperature at 240℃,reactor pressure at 5 MPa and reactor diameter of 2.5 m.
